Introduction

It's under US$4000. Aside from the $5000 Canon XL2, the next lowest cost
24p video camera is about US$19,500: the Panasonic AJ-SPX800.

With its introduction the DXV100, and its successor the DVX100A, instantly
became the hot cameras for indie digital filmmakers. The
24p-capable Canon XL2 only adds to the excitement. As a result there's a
lot of hype, hysteria, and FUD (fear, uncertainty, doubt) about them and
about 24p production in general.

I'll try to navigate through the hype, hysteria, and FUD to provide
factual material and rational analysis. I have the original DVX100 and I
can put it through its paces alongside a Sony DSR-PD150 (the de facto
standard in $4000 DV cameras) as well as the DSR-500, a higher-end
favorite among digital filmmakers. I'll also try to use various
post-production tools and see what works, and how.

Note: I focus here on the Panasonic DVX100-series cameras, but much of
what I talk about applies to the Canon XL2 and to the bigger 24p
Panasonics as well.

Cutting to the chase: the DVX100 is a very good camera for its price, even
ignoring its 24p capability. Perfect? Heck, no. It has all sorts of flaws
and omissions, just like any other $4000 camera. But for what you pay, you
get a lot; if you understand both the strengths and the weaknesses of this
camera, it can be a very powerful production tool.

And the second-generation camera, the AG-DVX100A, is even better. I've
scattered comments on the 100A throughout.

The page is a stream-of-consciousness ramble through various issues as I
collect information and generate tests. Don't expect a lot of organization
or comprehensive coverage (and don't bookmark anything here except the
page itself; anchors come and go).

The
DVX100A (and B)

The DVX100's successor, the DVX100A, was announced on 2003.11.19 at
InterBEE (International Broadcast Equipment Exhibition; Japan's own
version of the NAB show) in Chiba City, Japan.

The day before the announcement I had a loaner pre-production prototype in
my hot sweaty hands, courtesy of Stuart English at Panasonic.

I put it though its paces alongside my DVX100, and the full review is
currently available on DV.com
(registration required: not too onerous, and no, I haven't been spammed as
a result. DV needs the demographic data to justify ad rates to
advertisers, that's all).

Remember that this was a preliminary
review based on a pre-production camera. Some of the details may
have changed in production cameras, although little if anything appears to
have.

To summarize the changes made in the DVX100A as compared to the DVX100:

Delivery date? Shipping: folks
had them in their hot sweaty hands in January 2004, just as Panasonic
promised.

MSRP? US$3995. Reputable dealeras
have them as low as US$3500 (as of January 2004).

Is it worth getting a DVX100A model instead of a used or discounted
DVX100? The “plain old 100” is still a mighty fine camera. I still have my
100, and I haven't even begun
to exhaust its capabilities yet. I'll probably upgrade to a 100A at some
point, but it'll be driven by a specific job; I can't justify the upgrade
on its own merits unless those merits include significant paying gigs,
grin.

In late 2005, Panasonic announced the DVX100B. While the main purpose of
the B model was RoHS compliance (Reduction of Hazardous Substances in
manufacturing, required in the EU starting in 2006), Panasonic squeezed in
a few additional improvements, such as sharper EVF and flip-out LCDs, true
16x9 monitoring, more remotely-controllable functions, and FireWire scene
file transfer. See http://www.dvxuser.com/articles/100b/
for
details.

How is 24p recorded? What's
the difference between 24p and 24p Advanced?

The recorder (and indeed all the video I/O) runs at 29.97
frames/second, interlaced, all the time, regardless of what the camera is
doing.

When the camera is running in 60i or 30p, the incoming video is placed
into a frame buffer, compressed with the DV codec, and written to tape
and/or sent out FireWire. That same frame buffer feeds the analog outputs,
one field after the other. Whether the images come in interlaced or
progressive, every 30th of a second – well, every 29.97th, but let's keep
it simple for now – an image gets written to the frame buffer, and an
image gets played out: two fields compressed as a frame for FireWire and
recording, and two fields sent out one after the other for interlaced
analog I/O.

24p is a bit more complex. [Of course, it's really 23.976p, the
same way 30p is really 29.97p and 60i is really 59.94i, and even those
numbers are approximations. When the National Television Systems Committee
added color to the existing monochrome standard in 1953, they had to fudge
either the picture frequency or the audio subcarrier frequency by one part
in a thousand, to keep the color subcarrier from interfering with the
sound subcarrier. Sound won; NTSC pictures now run at 30 * 1000/1001 fps
(and that number is exact), and ensuing generations have
had to struggle with the peculiarities of drop-frame time code and
resetting their master clocks every day to account for drift. But I
digress...] 24 does not fit so cleanly into 30; for every four frames of
24p video that go by, five frames of 30p (or 60i) video go by. Another way
to look at it is that 24 frames of 24p video have to be squeezed,
stretched, and mashed into 60 fields of NTSC-compatible video; that's four
frames of 24p per ten fields of 60i.

There are several ways to do this; the AG-DVX100P and AJ-SDX900 offer two:
24p, which I call 24p Standard, and 24p Advanced.

24p Standard utilizes the same 2:3 or 3:2 pulldown cadence long
used to transfer 24fps film to NTSC video. The first 24p frame is written
to two fields of 60i video, the next is written to three, the next to two,
and the next to three again, as shown in the graphic.

This cadence offers the smoothest possible raw conversion between the
frame rates, and gives us the familiar judder of film transferred to tape.
There are a couple of things to notice about it:

1) The "A frame" is defined as the only frame of 24p that occupies exactly
one whole frame of 60i video with no overlap into adjacent frames.

2) The A, B, and D frames can be recovered by using two fields from the
same 60i frame. The C frame cannot be; it is split across field 2 of the
third (green) 60i frame and field 1 of the fourth (magenta) 60i frame. In
an intraframe-compressed format like DV, that's an important distinction:
the two fields of each 60i frame are compressed together, as a frame. If
the two fields are very similar, as happens in the red, yellow, and blue
frames, the compression uses a comparatively efficient "8x8 DCT" mode. If
the fields are very different, as happens in the green and magenta frames
when there's a lot of motion between the B, C, and D frames, a less
efficient 2x4x8 DCT is used, possibly leading to more image degradation in
those frames compared to their red, yellow, and blue companions.

Furthermore, the original A, B, and D frames can be copied in their
compressed form from the 60i video data into a new 24p data file,
but recovering the C frame requires decompressing the green and
magenta frames and recompressing them into a new, 24p DV frame. That puts
the C frame a generation down compared to A, B, and D.

If the 24p extraction tool uses white instead of superwhite codec ranges,
as Cinema Tools does, it will clip
whites in doing so – you really have to preprocess all your footage
prior to reverse telecine to pull superwhites and saturated colors into
range. Note that this is not necessarily an indictment of such tools:
codecs that run in a white-only range instead of a superwhite range can
eke a little bit more quality out of the in-range image, at the expense of
the out-of-range data. However, if you're using the extended dynamic range
that superwhites give you in acquisition, it means you have to add that
extra processing step to pull your superwhites back into range before
converting to 24p, lest the conversion hard-clip your C frames and remove
that creative control from your domain.

24p
Advanced uses a syncopated 2:3:3:2 pulldown cadence to stuff 24
frames into 60 fields. It's ever so slightly different in its playback;
the standard cadence of 2:3:2:3:2:3:2:3... evenly intersperses the "short"
and "long" frames, while 2:3:3:2:2:3:3:2... lumps two "short" frames
together followed by two "long" frames. The difference is subtle, but can
be seen on smooth pans or on regular in-frame motion, like the passage of
a train. In my experience so far, about half the people looking at a 24p
Advanced clip can see that the motion is a bit different, and half cannot.

But 24p Advanced isn't intended for making the 60i video look like film;
it's designed to allow the best possible recovery of the original 24
frames. You'll note that all four original frames can be recovered from
self-contained 60i frames; the green frame in 60i now contains the "extra"
B and C fields and can be discarded, since all the information for B is
contained in the yellow frame, and all the information for C is in the
magenta frame.

Extracting a true 24p clip from a 60i recording simply requires copying
the raw data for the red, yellow, magenta, and blue frames into a new 24p
file, skipping the green frame altogether. No decompression or
recompression is required, and all recovered 24p frames retain
first-generation quality. No clipping or other loss is incurred; you are
still working with all your frames in their first-generation glory in 24p.

Indeed, Cinema Tools goes one step farther: it gives you the choice of
either creating a new 24p file, or simply rewriting the Quicktime frame
pointers in the original file to skip over the green frames! Rewriting the
header is much faster (not that Cinema Tools is slow in writing a new
file), but your "new" 24p file is about 25% larger than it needs to be,
since it still contains the discarded frames, and you can no longer go
back to that file and play it as a 60i file: Cinema Tools has no "undo"
for rewriting the frame pointers.

When to shoot 24p? 24p
Advanced? 30p? 60i?

The general rule is to shoot 24p Advanced if you want to extract the
original 24 frames/second for a 24fps edit or film-out. Shoot 24p Standard
if you are going to stay on video and edit at 30 frames/seconds (60
fields/second, i.e., plain ol' video at NTSC frame rates), without
extracting the original 24 frames into a 24fps timeline. In more detail:

Shoot 24p Advanced for:

Post-production using tools that understand Advanced pulldown. 24p
Advanced footage can be turned into pure 24p footage more cleanly than
24p standard footage, because every frame in the pure 24p timeline is
pulled from a whole frame in the 24p Advanced footage, whereas the C
frame in 24p Standard footage is split across two different source
frames as discussed above.

Shoot 24p Standard for:

Getting the “film look” on video when you're staying on video and
editing at 29.97.

Intercutting with film transfers also using 3:2 pulldown, and
staying on video at 29.97.

Working with traditional film-on-tape tools that understand 3:2
pulldown, but not 2:3:3:2 advanced pulldown, when you need to
extract the 24p footage for true 24p processing.

Working alongside Canons and older Panasonics in Frame Movie Mode,
when you want to match their motion rendering.

You want the slightly "filmic" motion of 30p, but don't want to go
to 24p, and you aren't concerned about ever going to film or
converting to PAL.

Shoot 60i for:

Anything that you want to use as plain ol' video at NTSC frame
rates: in 60i, this camera makes pix that look (from a
motion-rendering standpoint) just like the pix from any other video
camera.

In other words, use 60i for everything that isn't supposed to “look
like film” and doesn't need progressive scan!

Again, these are general guidelines, not firm rules. However, I will state
one fairly firm rule: never use 30p if you think you might go out
to film or convert to PAL. In these cases stay with 60i or use one of the
24p modes. DVFilmin Austin says
they'll give you good looking 24fps film outs from 30p footage, but it's
much harder to do so and get clean motion, and even DVFilm recommends
against it. I don't know any other film-out place that will even try.

16x9?

The DVX100 is 4:3 only, although it has a built-in letterboxing mask
leaving about 372 scanlines (NTSC) shown: a bit taller than the 360 lines
of true letterboxed 16x9. Panasonic had a firm target of US$4000 or less,
and built-in 16x9 would have broken the bank.

The DVX100A adds a digital squeeze mode; in progressive it's as nice as a
360-line “upconversion” can look, although in interlaced I'd rate it very
slightly worse than a PD150's built-in 16x9. Pix in my review on dv.com.

Panasonic's own 72mm 16x9 anamorphic adapter, the AG-LA7200G, is available
with a list price of US$940 and street prices around $750-$850. It's
compact (2.5 inches / 6.5cm long) and lightweight (under a pound / .43kg).
In my work with it to date, I've been quite pleased. It's fully
zoom-through without vignetting, and usable at full aperture at wide
angles. As you zoom in, you'll need to stop down (also as you focus
closer); I've made a chart mapping the
combinations of zoom, focus, and iris necessary to retain critical
sharpness. At wide angles (and I mean wide: the adapter widens the
existing 4.5mm wide angle by about 33%!) there's some barrel distortion
visible (though no more than the un-adapted lens shows; the adapter adds
none of its own), but it's not so bad as to be unusable for most purposes.
At 6mm the lens is quite rectilinear with or without the anamorphic.

The adapter has a .5 inch / 1.2cm fixed "shorty" lens shade, really more
of a rim to protect the front element from scratches if the lens is set
face-down on a table. The front of the adapter is not threaded for filters
nor is it fitted for accessories, so adding a matte box / filter holder on
support rods is probably the way to go (see below).

Given the extreme depth of field at wide angle, I'd be tempted to
interpose any really necessary filter between the camera and the adapter
to avoid showing too much dust in the picture, and leave the rest of the
filtration for post. Before critical takes, I'll zoom out, manually focus
to MF14, and see all the dust on the front glass in sharp focus. I then
clean the lens with a microfiber cloth while watching the monitor!

There may have been some quality-control issues on the initial shipment of
these adapters. Early adopters have reported two problems: lenses fresh
out of the box with dust between the elements (which often shows up in the
pictures since the depth of field is so high), and a fragile lens coating
that peels off (!) when the lens is cleaned. I haven't seen either problem
on the four or five samples I've seen so far, and the one I bought is
internally spotless and undamaged by gentle cleaning.

Century Optics is reportedly
working on an anamorphic adapter. Optex is also said to be developing a
72mm native widescreen adapter. The current OpTex
adapter (distributed in the USA by ZGC)
can be fitted, but only works from 12mm to 45mm; any wider and it
vignettes. Street price on these 72mm native adapters (which should
also work on the Canon XL1) will probably run between US$1500 and $2000.

There is some concern that the lens front on the DVX100 may not be sturdy
enough to support the big adapters and that support rods may be needed. A
support rod adapter will of course add to the cost, but the upside is
that, if properly designed, the rods will accept standard cine
accessories, and CineTech
and others now offer clamp-on lens adapter rings for follow-focus controls
that ride on standard 15mm rods, as on this
PD150. Read on...

Cine-Style Accessories

Cine-style accessories are now available for the DVX100. 16x9 Inc
supplies a variety of standard Chrosziel
accessories that work well fitted to the DVX100, riding on 15mm
rods. Century Optics provides a follow-focus
gear that meshes with standard cine follow-focus setups; it
includes a white focus-marks scale. Chrosziel builds a lightweight
support rod system for the DVX100, part # 401-46, MSRP US$385—as of
July 2003, Abel Cine Tech
sells it for US$327 (this price is for the camera plate with the rods;
anything you want to put onthe rods is an added cost, of
course!). The Chrosziel kit, including the 4x4 sunshade, currently
works with the stock lens and perhaps with the smaller lens adapters,
but if you use it with the LA7200 anamorphic adapter, you'll need to
cut back the short shade on the adapter to fit. ZGC
offers this service for around $150. The rig shown was seen at DV Expo
East 2003 in Century's booth.

It appears that CineTech
(not the same company as Abel Cine Tech!) now has both a camera
plate with 15mm rods and a focus gear designed for the DVX100.
CineTech kit is more expensive, but it's premium stuff: cross-braces
drilled out for lightness; elegant wood focus knobs. CineTech offers a
large swing-out matte box with filter holders that should work with
most lens adapters; see the CineTech
kit fitted to a Sony DSR-PD150.

Jerry Kosan makes a nice selection of cine-style accessories (matte
box, follow-focus, handgrips, etc.) for the DVX100; his XL1
accessories should work fine on the XL2, too. www.jbkcinequipt.com

Does a follow-focus with focusing scale make sense? Certainly! Once
the DVX100 is powered up, calibrate the ring to infinity and set the
focus limits on the adapter ring; the focus will track consistently
from then on. As long as you don't turn it past the limits, it will
repeatably hit any marks you make on the white focusing scale (at
least if you don't spin the ring too quickly or too slowly; but I have
not been able to fool the zoom at all in my tests).

(Thanks to Jeff Giordano at 16x9 and Jeff Lawson at Abel
Cine Tech for their help with the support rod details!)

Handling the Zoom

Unlike most low-cost cameras, the DVX100 has a mechanically-coupled
zoom. Unfortunately the short throw of the zoom ring (90 degrees from
full wide to full tele) and its light feel make it very
sensitive to minor motions. It's quite difficult to do a smooth, slow
creep or to ease into or out of a move with your bare hands. The
DVX100A is much better in this regard as it has enough viscous damping
to allow a smooth manual zoom–but a delicate touch is still required.

Normally one adds a zoom lever to mechanical lenses to smooth out
one's operations. There is a tapped socket on the zoom ring, but it's
very small and any lever threaded to fit would be in constant danger
of breaking off. What to do?

I took a piece of string about two feet (70cm) long and taped each end
to the zoom ring with small bits of gaffer tape, so that it formed a
loop around the lens.

With right hand on the tripod handle and left hand tugging gently on
the loop, I can now zoom slowly and smoothly. Because the feel of the
zoom is so light – there's so little drag – all it takes is a gentle
pull to turn the zoom ring. It looks funny, but it works; it's hard to
break off; and the price is right!

The ZOE-DVX
zoom controller allows smooth, stepless zooming using the camera's
built-in motor, but it's limited in its slowest speeds by the nature
of the the DVX100's motorized zoom system (the Varizoom
controller is almost certainly similarly constrained). Getting a fully
smooth motorized zoom that can cleanly ease in and out of moves will
probably require a gear-coupled external motor riding on the support
rods described above. Sadly, I
know of no such zoom controllers at present.

Focusing by the numbers

The DVX100, like most servo-lens cameras, doesn't have an engraved
focus scale. It does, however, have a focus readout in the viewfinder,
which runs from 00 (near) to 99 (far) in arbitrary numbers. Eric
Petersen has posted a focus
chart on his site translating the numbers into both English and
metric measurements making tape-measure use practical with the camera;
sadly, the chart only lists focus numbers from 50 ("50%") upwards.
(The lower numbers are only available when the lens is wider than full
telephoto; the wider the lens, the more near-focus points are
available.)

I've found that focusing by the numbers in the finder works just as
well: Once I set my marks and memorize the numbers, I can easily and
repeatably return to them. If the LCD is flipped around and folded
back against the camera, a 1st AC or focus-pulling assistant can use
the numbers, too.

Why no colorbars /
gain-up / autofocus in progressive mode?

The DVX100A does allow colorbars, gain-up (to +12dB), and “focus
assist” in progressive, but the DVX100 does not.

Why no colorbars? Only Panasonic knows... my guess is that
they're being generated in a part of the 60i pipeline bypassed or
disabled in progressive-scan modes. No, it makes no sense on the face
of it, but I've seen enough similar bizarre limitations in IC designs
that I wouldn't rule it out. Fixed in the DVX100A.

Gain up? Gain up in 24p was present in the prototypes if the
scuttlebutt is correct. Panny pulled it, they say, because “all the
filmmakers they talked to said they wouldn't use it”. An iffy call
perhaps (what about those documentary shooters who need gain
boost?), although the gain-up chroma noise is such that I'm not sure
I'd use it (remember that noise is 1.4x worse in proscan because of
single-row readout; signal drops by half but noise drops only by one
over the square root of two).

Another reason I've heard from the Panny folks is that gain boost
screws up the Cine-like gamma computations. As Cine-like gamma can be
selected in interlace and the gain boosted with no more than the
expected deleterious effects of added noise, I find that explanation
puzzling.

I'm happy to report that gain-up on the AJ-SDX900 is available in 24p
modes, and it looks very clean. The DVX100A allows it, too.

Autofocus? Panasonic says that autofocus hunting is too
noticeable on the big screen and that's why they turned it off in 24p.
I only wish the EVF were sharper so I could manually focus with
assurance (can I transplant my PD150's EVF? Or steal the CRT off the
DSR-500 or the AJ-SDX900? The DVX100A adds a peaking function called
EVF DTL that helps out considerably).

There's another reason, too, and this one is a killer. 24p autofocus
would run, at best, 2.5x slower in 24p mode than in 60i mode, because
its raw data is only coming in 40% as quickly. My gut impression is
that it'd be only marginally useful at best. If Panasonic boosted the
servo gain on it to try to improve speed, it'd oscillate instead of
settling down to a steady state.

The DVX100A allows autofocus in progressiven, though Panasonic
sensibly refers to it as “focus assist”. It runs much more slowly in
24p than in 60i (about 1/4 of the speed!) so it's really useful only
for setting up on static subjects. When things are moving, you still
need to rack manually.

As it is, you can focus by the numbers
using the onscreen readouts (in scripted or other controllable
circumstances), so the problem is considerably lessened outside of
run'n'gun situations. When you have to focus on the run, and there's
no big, sharp monitor available, I find it's much easier to focus the
DVX100 with the flip-out LCD than with the EVF. Size matters.

Gamma settings

Relative gamma curves for AG-DVX100

The DVX100 allows the selection of three different gamma curves as
shown (The DVX100A has several additional gamma curves, to be posted
in the future). The curves were derived by imaging a horizontal luma
ramp created in Photoshop and displayed onscreen, and observing the
camera's output on a waveform monitor while changing between gamma
settings. Thus the curves are relative to one another: the exact
curvatures and spacings of the curves cannot be determined from such a
test.

High and Low are variations on Normal and are useful in modifying
overall tonal balance without changing the way extreme highlights are
handled. A fixed knee at around 93% appears to be in effect regardless
of scene brightness, above which the tonal curve is flattened somewhat
severely to eke out as much highlight detail as possible before
clipping sets in, and to smooth the visual transition from normal
tonal rendering to the undifferentiated flat white of severe
overexposure.

The price one pays for the knee are a noticeable transition in tonal
gradients at the knee point, and some hue errors as colored highlights
are differentially compressed. These errors are common to knee
circuits and are not unique to this camera.

By comparison, the Sony PD150 appears to use a content-dependent knee
like the "Dynamic Contrast Control" on its big brothers the DSR-300,
370, 500, and 570. The knee point on the PD150 seems to vary between
80% and 100% depending on the amount of bright elements in the scene,
and the slope above the knee is less harshly compressed, so the
visibility of tonal gradient changes and hue errors is somewhat less.
However the effective latitudes of the DVX100P and the PD150 are
extremely close; the PD150's lower knee point (at its maximal effect)
is offset by its lower peak compression.

Furthermore, while the Sony would seem to hold colors more accurately
as brightness is pushed above 100%, the Panasonic appears to hold more
luma detail: overexposed foliage on the Sony holds its hue but "mushes
out" any detail whereas the Panasonic's rendering will bleach out more
color but preserve more detail. In practice I cannot yet predict which
camera will make a more pleasing rendering of a given scene; sometimes
the Panasonic does, and sometimes the Sony does.

Cine-like gamma does as little image-distorting processing as
possible, giving you the widest tonal scale it can without knee
compression or hue distortion. At first glance Cine-like images look
flat and a bit underexposed, but when watched in a darkened room (as
films are watched in theaters) they look highly naturalistic and –
dare I say it? – more film-like than images shot with the other gamma
settings.

The caveat is that there is NO highlight compression at all: the tonal
scale runs smoothly right up to 109% and then whacks right into a flat
white ceiling. Unless your lighting conditions are well controlled,
you will almost certainly have some highlights in the image over 109%,
and they may stand out as disembodied pools of undifferentiated white.
To fully exploit Cine-like gamma requires you to handle these
highlights yourself in post production; you can't just leave them in,
uncorrected, and let the flattened knee of the curve smooth the
transition between a normal tonal scale and overexposure, because
Cine-like gamma has no such knee.

Improved latitude on the DVX100A:

The DVX100A has three different cine gammas, CINE-LIKE, CINE-LIKE_D
(dynamic range) and CINE-LIKE_V (video). All three have knees.
CINE_LIKE is for compatibility with the DVX100; think of the other two
as the counterparts to “film rec.” and “video rec.” on the Varicam:
similar, but with _v boosting midtones, more like the normal video
gammas do.

Here are some frame grabs that illustrate the differences:

All
images shot at f/2.8, 60i @ 1/60 sec, +6dB gain. Note that some
computer monitors (including many LCDs) crush shadows and can't
be adjusted to show them properly; look at these pix for
highlight detail and clipping and for overall gamma, not
shadows.

Matrix settings

The camera has three color matrix settings: Normal, Fluorescent, and
Cine-like. Fluorescent boosts the reds compared to normal, giving richer
flesh tones under red-deficient fluorescent lighting. Cine-like appears to
boost all colors equally, as if one left the camera in Normal but then
increased color saturation overall.

The A model adds “Enriched” to the matrices, and all color renditions are
a bit different. Descriptions and vectorscope pix in my review at dv.com.

Strange noises &
Construction

When the camera is switched off or put into VCR mode, parts of the lens
assembly (possibly the optical stabilizer or the focus mechanism) clunk
loudly as the camera is tipped back and forth. This is normal.

The autofocus motor makes a lot of noise as it locks in on a focus point.
You'll hear it through the built-in mics, and you'll hear it by ear in a
quiet room. It's noticeable because it's intermittent and because most
other cameras are quieter in this regard, but usually the autofocus motor
isn't much louder than the zoom motor or the tape transport.

The camera's main casting is magnesium, which contributes to its high
strength-to-weight ratio. I was surprised to see the lens barrel is part
of the casting: on the finished camera I had the impression it was
plastic.

So far, my camera has held up solidly despite a couple of inadvertent hard
knocks, though one correspondent reports that his flip-out screen was
damaged when the tripod-mounted camera was knocked over and fell on the
floor.

Why do the DVX100 stills at
24p.com look so different?

Michael Phillips had enlargements of DVX100 frames posted at 24p.com
(partially available
at
archive.org; look at the differences in the red patches on the
GretagMacbeth chart images) using two different pathways from DV to
RGB: exports using the Apple DV codec, and exports using the Avid XPressDV
3.5 codec. The frames look quite different in terms of tonal scale and
chroma edges. Here's why:

Gamma

Unlike every other DV codec I've seen, the Apple codec gamma-corrects
imagery to compensate for the difference between a video display's 2.2
gamma and the Mac's standard 1.8 display gamma. Apple does it so that what
you see in on the Mac's screen translates well to video and vice versa
(unless, like me, you're already running your Mac at 2.2 display gamma for
working in Photoshop and Illustrator, and with all the other video
codecs available!).

It makes side-by-side comparison between Apple DV exports and other DV
exports very difficult unless you “uncorrect” the gamma in the picture
prior to export. It also means that you have to precorrect CGI
(computer-generated imagery) with a complementary gamma correction if you
want that CGI accurately portrayed on video when using Apple DV.

I should mention that the gamma change is bidirectional -- what's done
going from Y'CrCb to RGB is undone in the other direction -- so it won't
accumulate over multiple compression cycles. But you do need to take it
into account when exporting from Apple DV to other formats, or importing
other formats into Apple DV.

I have lobbied for a prefs setting to enable/disable gamma tweaking to no
avail: the Apple DV codec has that built-in gamma conversion (about 1.22
in one direction and 0.82 in the other) and we just have to live with it
if we want to use that codec.

To correct material imported into Apple DV, try a gamma precorrection of
1.228. To gamma-correct on export from Apple DV, 0.824 works pretty well
(with a tip of the hat to Chris
Meyer for these numbers!).

Chroma
Interpolation

The Avid exports show fairly smooth chroma transitions, while the Apple
codec clearly shows the “steppy edges” in chroma that are the bane of DV's
existence.

This is not a bug in the Apple codec per se (although if you're decoding
to uncompressed for post work, it requires an extra processing step; see
below). There is only one chroma sample horizontally for every four luma
samples. The Apple codec outputs a 4:4:4 RGB image by replicating each
color sample across the next three pixels; it does not try to smooth or
interpolate the data between samples.

The Avid codec applies a low-pass filter to the decoded chroma data to
more smoothly interpolate between samples (notice how the saturation on
any color patch starts fading out before the edge of the patch is
reached). As a result the Avid codec makes a more pleasing RGB image on
the 1st generation decompression, but if carried through a couple of
cycles the color will soften and smear more than occurs with the Apple
codec.

On the SDI capture (not currently posted, but it looked very much like the
Avid exports) there is also filtering & interpolation going on, the
details of which depend on how one is getting the SDI signal from the DV
original: the 4:1:1 to 4:2:2 conversion in the deck's hardware almost
certainly interpolates the chroma prior to output, and the 4:2:2 codec
used in the NLE may likewise low-pass or interpolate further to get 4:4:4.

[Generally speaking, the Apple DV codec is designed to preserve the
original 4:1:1 data as accurately as possible over multiple generations.
Compared to Avid, it hold more high-frequency data in the luma, and better
preserves the chroma – but it is also more prone to “mosquito noise”
compression artifacts as a result of preserving the hard-to-compress
detail, and its RGB decodes have unsmoothed, steppy edges.

The Avid DV codec, by contrast, was specifically optimized for the fewest
compression artifacts and the most visually pleasing picture, at the
expense of some high-frequency detail. Compared to Apple, its images often
look “cleaner” in the first generation, albeit a bit softer (look at the
text on the color-checker chart, for example). ]

If all you're doing is capturing via FireWire and editing in DV25, the
Apple codec in my experience holds more fine detail and preserves the
image better over multiple generations (but compressing sharp-edged CGI
requires more aggressive low-pass filtering on input to avoid generating
mosquito noise). However, you will see the sharp-edged, unfiltered chroma
on extracted stills, just like the 24p samples show.

In such a case the Avid codec yields nicer stills, but you'll see a
progressive softening and blurring of chroma with each generation – no big
deal on 1 generation (and don't get me wrong, the Avid codec is, along
with Apple's, among the best I've seen) but if you're going between an NLE
and a compositing app using DV25 compression as your intermediate [hint:
don't do this], or repurposing material from previously-edited DV material
on a new DV project, the softening from multiple passes can be noticeable.

Remember, if you're going back out FireWire, the final decode and
associated chroma interpolation is done by the hardware codec in the VTR,
and the difference between the Apple and Avid codecs and the way they
interpolate chroma for RGB viewing is irrelevant!

If, however, you're bumping up to uncompressed for editing and output, you
do want to perform some form of chroma smoothing or interpolation
upon initial decompression from 4:1:1 DV to 4:2:2 uncompressed.
Likewise, doing a chroma-key in DV without chroma smoothing is an exercise
in frustration, and as the 24p pix show, it's a useful thing to do before
exporting stills.

What to do? You can use a codec that performs the smoothing by default
(like Avid), or by choice (Matrox's software VfW codecs let you switch
chroma interpolation on and off), or use the Apple DV codec and add a
chroma-smoothing filter. I have one for Final Cut Pro here.

But, I repeat, this is only useful/necessary if/when you're bumping up to
a higher-resolution format, exporting a still image, or chroma-keying – it
doesn't do you any good when decompressing DV only to recompress to DV.

So it's a tradeoff, as it always is when going between higher- and
lower-resolution color spaces: preserve the low-res data unfiltered, with
the resulting visible artifacts in the higher-res space, or smooth the
data for better display at the expense of multigeneration accuracy.

The chroma-patterning
problem

Close examination of DVX100 and DVX100A pix reveal that highly saturated
colors of a certain width, or the edges of large solid areas of saturated
color, show a position-dependent variation in saturation. At approximately
60 positions evenly spaced across the screen, saturated color details or
edges will desaturate slightly. It's completely unnoticeable on static
images or in the interior of large colored areas, but is revealed on edges
and details in slow pans, as the colors “pulsate” slightly.

I've got a sample clip here
(loads in a new window). I took the highlighted 72x48 pixel area from a
slow pan past a bookshelf. The arrows at the bottom of the clip show the
position of each four-pixel-wide DV chroma sample; the arrowheads at the
top mark locations of peak chroma saturation. The sample is twice normal
size, and the pixels were left as square, not resampled to account for
their original 0.9 aspect ratio. The source was decompressed with Apple's
codec (which does no chroma smoothing, as described above)
with a slight horizontal chroma blur added to reduce chroma aliasing prior
to re-encoding to Sorenson3. The resulting image is very close to what
you'd see looking at a video output; the recompression for the web has not
added nor subtracted any substantial artifacts.

As the sample shows, it's most visible in bright, saturated reds and
oranges. In practice, I'll see it most often in traffic lights, orange
traffic cones, backlit store signage, and similar footage. It also shows
up on strongly saturated greens and blues (which has implications for
chroma-key work) and is present on less saturated colors as boosting
saturation in the NLE will show, but such errors are visible much less
frequently than in the bright reds.

How bad is it, really? I didn't notice it myself until I'd had the camera
for two weeks, and only then when I had the monitor's saturation maxed out
for a color test. Now I know what to look for, though, I can see it in
other pix both from my camera and from others even on normally set up
displays.

But to put it in context, the horizontal aliasing from a PD150 with the
"sharpness" set to the default position or higher is more immediately
noticeable, to my eye at least, and I don't see people getting upset about
that.

I've shot a fair bit more with the camera since first seeing saturation
patterning, including many shots with bright reds in clothing and in
backgrounds. I'm pleased to say that the visibility of the patterning is
minimal or nonexistent on the vast majority of things I've shot.

However it does affect chroma keying considerably, I'm sorry to say; I
would recommend against planning any detailed chroma-keying with
DVX100 footage without performing careful tests first. Both the hue and
saturation channels are affected by 60-times-across-the-picture fixed
patterning, and keys depending primarily on hue and/or saturation tend to
show the pattern in the edges of moving items. Luma keys, however, are
excellent, and chroma keys where luma is the primary edge-definer (chroma
being used only to differentiate similar tonalities in the foreground and
background) can be quite acceptable. Test, test, test!

Audio / video sync

While I was shooting some A/B comparisons using a slate (filmmaker's
clapstick, seen in the graphic at the top of the page), I found that the
audio on my DVX100 leads the video by one frame in 60i mode. DVFilm reports
that all 24P Advanced footage has a 2 frame audio lead.

The audio advance is constant; it does not drift during a shot or from the
beginning of the tape to its end.

The audio advance happens during recording: my 60i DVX100 source tape
played back in a DHR-1000 with jog audio enabled plays the “snap” of the
clapstick a frame or two ahead of the picture where the stick hits the
slate. Capturing the clips into a variety of NLEs confirms the one frame
audio advance in 60i, and up to two frames in the progressive modes.

Don't panic!
While this is annoying, it's not crippling, and you can fix
it in post (yes, yes, I know: why should we have to fix it in post?
Don't like it? It's a free country; go get an HDC27 Varicam or F900
CineAlta instead. It's only money, i.e., $65,000+ to buy or $1200+/day to
rent. Me, I'll just fix it in post). It's also mostly
fixed in the DVX100A; see below.

And if you're shooting 60i material, most folks won't even notice it. It
took me a couple of months to find it, and no one else seemed to notice
for about the same period of time. It ain't the end of the world.

How is this possible? Consider that a frame's worth of video must be
buffered before it can be compressed and written to tape, even in 60i. For
audio to line up properly, it has to be buffered (delayed) accordingly
before it's multiplexed with the compressed DV data. It appears that there
is no audio buffer in the DVX100. But this turns out not to be unique to
the AG-DVX100! Read on... (Don't care to read on? Cut
to the chase instead.)

Stuart English, VP of Marketing for Panasonic Broadcast, explains it this
way (as originally posted on 2-pop's AG-DVX100
forum on 2003.01.10 and reprinted with Stuart's permission):

[A]ll the
DVX100's out there will behave the same, they have the same audio /
video sync characteristic...

...[A]ll professional DV camcorders will most likely share this
characteristic of audio leading the video. We constructed an
electronic audio / video pulse test rig to verify that, and then
tested the following DVX-100, PD150, XL-1, GY-300. All except the
DVX100 (in 60i mode) have a one field advance between audio relative
to video. Based on our test, none have a zero field advance as has
been claimed...

Perhaps due to the characteristics of the frame output capable CCD
imager, the DVX100 in 60i mode has a two field advance between audio
and video. Yes, this is more, but it is something that can be
compensated for in an NLE application - just pick up the audio
timeline and bump it by 1 whole frame...

Why does the audio advance happen?

Unlike an analog tube camera (where the video lines are scanned and
recorded in real time, and the audio is recorded in real time) CCD
cameras accumulate charge over the duration of the field (or
frame)and then dump that charge at the end of the field (or
frame)into the DSP circuits which perform additional signal
processing.

Meanwhile the audio is still recorded in real time.

So the signal on tape is video delayed by at least one field, and in
the case of the DVX100 in 60i mode, by one frame. The only way out
of this is to add an audio delay circuit in to the camera audio
paths to add an equal amount to delay to the audio which would put
the audio and video in sync again on tape.

At the DV camcorder price level it is too expensive to include such
an audio compensation delay, the easiest solution in practice is to
slip audio in the NLE if it is causing any annoyance.

Regarding people's comments about "my camcorder is in sync" - there
are other factors at work that can bias observations for example-
Sound travels much slower than light. Zooming in on a subject 16ft
away from you the video arrives approx 16ms earlier than the audio -
that's one field time. 32 ft is two field times. So audio on tape
might seem to be in sync, or even have the audio follow video. But
if you put a mic on that person, and line recorded the audio, it
wouldn't be in sync, it would lead again.

b) If you watched your footage on an LCD or plasma monitor, the
video would seem to be more delayed than if watched on a CRT - the
LCD and plasma have image delay in them because they are not real
time scanning devices, they read the data in, convert to progressive
scan, and only then display it.

c) When working in 24P mode, there are two other issues - the video
frame rate is lower so it is less certain when the video event
actually happened, and due to the need to add 3:2 or ADV pulldown,
the apparent audio lead / video delay "wobbles". We think that it
should still be 1 frame i.e 2 fields, but because of 2:3 pulldown on
the tape it may look like it is sometimes 3 fields. The only way to
really test is to use DVFilm to remove the 3:2 pulldown and look at
the 24P native footage on the NLE timeline.

Again, audio advance or delay is easily removed by NLE
application... as long as the advance or delay is consistent, which
it is.

“Now how much would you pay? But wait, there's more!” I went back to study
my sync tests and shoot new ones. Instead of the clapstick and its
temporal uncertainties, I instead flicked a business card past my finger:
in the still frames, I can see roughly where in time the card hit my
finger as it motion-blurs past. I shot tens of seconds while flipping the
card rapidly back and forth about four feet in front of the cameras using
their own microphones; played it back frame-by-frame on a VTR; and studied
the clips in both Final Cut Pro 3 (a.k.a. FCP) and Premiere 6.0 on Windows
2000 (using Microsoft's DirectX 8 DV infrastructure). I found some very
interesting things...

Capturing in Final Cut Pro 3 on OS X (either 10.1.5, QT 5, FCP
3.0.2; or 10.2.3, QT 6.1, FCP 3.0.4) gives variable delay results: the
same clip, shot on any camera, and captured three or four times, shows
A/V delays differing by up to almost one frame's time (about 30msec
variation) between the different captures. Thus, using clips captured
in FCP, unless one has a “sync check” reference as described below, one
cannot make definitive statements about the exact value of the A/V
delay, only statements about relative delays between cameras
used in the captured clip. Captures in Premiere always line up almost
exactly as far as I can see (within 1/10 of a frame or better). (Final
Cut Pro 4 on OS X 10.2 fixes sync uncertainty.)

Within the same capture (i.e., capture of a tape segment containing
footage shot on the Panasonic and on a PD150), the Panasonic 60i
footage appears to show one frame (two fields) more delay than the
PD150's footage does.

Within the same capture, Panasonic 30p footage appears to have one
field more delay than 60i footage does. I re-ran my earlier tests with
the shutter set to 1/30 (i.e., as close to a 360º shutter or 100% duty
cycle as one can get) and it does appear that 30p footage incurs a
3-field advance instead of a 2-field advance.

24p footage shows the “variable wobble” as Stuart explains, with the
apparent delay being 1-2 fields worse than 60i footage.

Single-framing on a DHR-1000 with jog audio shows a 2-field advance
on the Panasonic at 60i; what appears to be 3 fields at 30p; 3-4
fields at 24p or 24p Advanced. The venerable DCR-VX1000, and the
$15,000 DSR-500WS both appear to play back with one field of advance!
The Sony PD150 appears to play in perfect sync.

Examination of the clips in Premiere confirms these results. The
PD150 is dead-on in sync while the old VX1000 and the expensive,
professional (but several-year-old) DSR-500 show a 1 field advance.
The DVX100 is 2 fields advanced in 60i, 3 in 30p, and 3-4 in 24p and
24p Advanced (still viewed as 60i source clips).

Item #1: I've been using FCP since it lets me see both fields (100%, Show
as Square Pixels unchecked) and audio waveforms at the same time in nice
big windows. My two captures last weekend using Premiere on Windows didn't
show any apparent A/V uncertainty; my Premiere captures today confirm
that. (Furthermore, Premiere shows me both fields merged in its monitor
window, and with the timeline expanded as much as possible it's as usable
as FCP's in observing A/V delay, although one has to squint more at
Premiere's smaller audio waveforms.)

To test the NLEs' timings, I shot “sync check” samples with multiple
starts and stops using both the DVX100 and the PD150, alternating between
(a) a shot of my computer's speakers with loud audio, and (b) colorbars
(or the lens capped) with silence. DV audio is interleaved with video data
within the frame, so even if there is A/V delay in the process, the cuts
between shots should show perfect sync: wiggly audio waveforms for the
entire frame in the shots of the speakers, flat audio waveforms for the
black or bars. I then followed these sync checks with my flipping-card
routine so that the sync check and camera check could be captured as a
single clip.

Using the sync check shots, I verified that FCP 3 captures clips with a
variable relationship between audio and video (FCP 4 is much better in
this regard, especially on OS X 10.2). In the best case, perfect A/V sync
is captured to within about 1/10 frame. In the worst case, audio leads
video by almost a frame (32 msec). However, using the offset on any given
capture revealed by the sync check let me validate the camera check shots
with a higher degree of confidence, since I was able to factor out FCP's
variable capture timing.

Captures into Premiere showed only a tiny variation in A/V sync check
shots. They varied between perfect sync and audio lagging very slightly
(well within 1/10 frame) as far as I can see by squinting at the timeline.
I reverified all my camera checks in Premiere and found that the camera
A/V timing relationships I had seen in FCP were repeated in Premiere.

Item #2 tracks with both Stuart's explanation and (according to Stuart)
Michael Phillips' test results showing a one-frame (two-field) delay, if
we assume that the PD150 is in fact in perfect sync.

Items 5 and 6 are most interesting. While there is some uncertainty in my
VCR playback tests as the DHR-1000 jogs by frames but shows only the
second field of each frame (the one more temporally advanced, i.e., the
one most likely to line up with advanced audio), the Premiere tests
showing waveforms and both fields in the frame confirm them. (Side note:
The DVX100 jogs by fields, the only low-cost DV device I know of that does
so. Unfortunately it does not play audio when jogging.)

In the PD150's case, I never was able to detect even a field's difference
between picture and sound. It was always dead-on perfect, in over 50
card-flipping events. This conflicts with Stuart's test results. (Stuart's
tests monitor the audio and video analog outputs on a dual-trace
oscilloscope and look for the line-up between the burst of sound and the
flash of light from a special test rig he built, so the results of our
tests are not directly comparable. I do not have the time presently to
replicate his test setup so I can't comment further on the discrepancy
between our results).

So I shot several more tests. The sync check shots confirmed perfect
capture sync in Premier within 1/10 frame. The PD150 camera checks always
showed what looked like perfect sync, or, if anything, up to 1/2-field
(1/4 frame) of delay in the audio!

I find it odd that the PD150 appears to be field-accurate while the
DSR-500 is off by one, but the PD150 is a newer camera and possibly it has
a digital audio delay while the older DSR-500 does not. If the AG-DVX100
is indeed one frame advanced in 60i, my tests would indicate that the
PD150 must be sync, because it's two fields less advanced than the DVX100
when footage from both cameras, captured in the same clip, is compared in
FCP or in Premiere. For what it's worth, my PD150 is serial #1005564, and
it came from the factory with the “audio noise fix”.

Running the 24p Advanced footage from a “perfectly synced” FCP capture
through DVFilm's Maker with
zero frames delay correction and loading into a 24p FCP sequence shows an
apparent advance of two frames, or four fields – just as Marcus van Bavel
at DVFilm observes. Thus the 2 frame delay that the latest versions of
Maker provide by default when extracting 24p footage looks to be a good
fix.
So, a quick summary of what I see based on FCP and Premiere tests and on
DHR-1000 jog-mode playback:

Camera, Mode

Audio Advance

PD150, 60i

0 fields, perfect!

VX1000, 60i

1 field

DSR-500, 60i

1 field

DVX100, 60i

2 fields

DVX100, 30p (played as 60i)

3 fields

DVX100, 24p (played as 60i)

3 - 4 fields

DVX100, 24p (played as 24p)

4 fields / 2 frames

DVX100A, 60i or 30p

0 fields, perfect!

DVX100A, 24p

lags
about 1/60 sec

BTW, I should mention that I worked with Stuart ten years ago at Abekas
Video Systems. Yes, he's in marketing (grin), but I've never known him to
fudge the truth. If he says he saw a 1 field advance in the PD150 I
believe him; we just need to determine why we're seeing different things.

Now, how do you deal with it?

DVFilm's Maker program, as of
version 1.06c, incorporates a “delay audio” option to correct the audio
advance, useful if you're extracting 24p from the 60i original.

In-sync's Blade 2 24p-native NLE
lets you set the audio advance during capture.

Final Cut Pro 4 includes
a "DVX-100 [sic] Audio Sync Tool" allowing you to tweak the A/V sync as
you see fit. It's not installed by default: Insert the installation disk,
and drag the plugin from Final Cut Pro 4 > Extras > DV Camera
Tuner Scripts to [your hard disk] > Library > Application
Support > Final Cut Pro System Support > Plugins. When you
restart FCP 4, you'll have an "Offset Audio Sync" option in the Tools menu
that lets you adjust the sync for one or more selected clips. The default
setting of 2 frames is usually correct for the DVX100's 24p footage.

If you're editing 60i directly or using Cinema Tools or other 24p
extractors, you can manually slip the audio in your NLE a frame or two to
compensate.

And other NLEs may have manual or automatic compensations for the DVX100;
just because I don't list 'em doesn't mean they don't exist.

Autoexposure

In a few of the scenes I've shot on auto-iris, I've seen a slight
“steppiness” to iris changes. Instead of smoothly changing from one
setting to another as the light levels in the scene change, the iris
adjusts in small jumps, just barely visible on the picture monitor and on
the waveform monitor.

Fast changes look clean, but slow, gradual changes, typically less than a
stop every two seconds, tend to show it. Each step is very small, finer
than the steps incurred in manual iris setting. The little jumps are
slight enough that it took repeated viewing of a scene to confirm that I
was seeing something. It's probably happening on faster changes too, but
the speed of the change makes the steppiness unnoticeable. I also find
that it's very, very hard to make this happen on purpose.

Another reason to run in manual-iris mode for critical work (which we all
do anyway, of course. Right?).

Cleaning the lens

Warning:
Cleaning the lens must be done carefully to avoid damaging it, as is true
with any lens. Removing the anti-reflection plate as described here may
void your warranty. In the process, your lens is subject to damage from
fingers, screwdrivers, loose screws, and the metal edge of the plate. It
is also very easy to lose the tiny screws. Follow this procedure at
your own risk!

The Leica lens has an anti-reflection plate mounted in front of it; it's
that thing with the rectangular cutout and with the lens data printed on
it. It's there to cut down flare and reflections.

Unfortunately it also makes it hard to clean the lens. With care, you can
remove the two screws that hold it in. It lifts off easily, giving you
access to the entire front surface of the lens (alternatively: tip the
camera downwards, and both the screws and the plate will fall free of
their own accord). After cleaning the lens you should replace the
anti-reflection plate.

Because this lens goes so wide, and because the camera uses 1/3" CCDs,
dust or smudges on the front element are easily seen in DVX100 images. The
supplied lens cap doesn't help; it's so finicky in its attachment that it
frequently jumps around as you're attaching it or removing it, often
transferring finger-cooties to the lens as it flops about.

LINKS

Not comprehensive by a long shot, but enough to get you started... just
watch out for the FUD! On the discussion lists especially there are lots
of very authoritative statements that are just plain wrong. I don't think
it's deliberate, but I see a lot of folks getting in way over their heads
with technical explanations based on a lack of understanding or a
misunderstanding of how things work.

John Beale
does great work exploring the camera's operating characteristics and
posting useful data (I am puzzled by his audio tests as other
competent testers have not seen the same comb filtering, but aside
from that I can't disagree with anything he's found).

I review the camera for DV
Magazine (on the website, browse “Reviews” and scroll down. The
DVX100A sneak peek was under “Features”. Offline?).

AG-DVX100 - discussions

Tools for editing/extracting 24p Advanced 2:3:3:2 footage & how
to do it

DVFilm's DVFilm
Maker, $95, converts 24p Advanced footage from 60i to 24p
without decompressing/recompressing. Maker also converts 24p back to
60i using either standard or advanced pulldown. Very cool tool.
Mac/Windows.

Apple's Cinema Tools,
now bundled with Final
Cut Pro / Final Cut Studio, handles 24p Standard and Advanced.
Mac. Final Cut Pro 4.0 and later can capture 24p Advanced directly
either during capture or after the fact. (Also note that the
lower-cost Final Cut Express cannot edit a 24p timeline.)
While FCP can edit in 24p, it can't print 24p back to tape using
anything other than 2:2:2:4 pulldown unless you have a fast Mac (FCP
4.0 and 4.1 needed something faster than my 800-867MHz Macs, but FCP
4.5, a.k.a. FCP HD, will add 2:3:2:3 or 2:3:3:2 pulldown on
these machines). And FCP has no way to render a 24p timeline
to a 60i file! Maker (above) is still a necessary tool for some of us.

Working with
the Panasonic AG-DVX100, Final Cut Pro and Cinema Tools, by
Andrew Lau on LAFCPUG, discusses basic Cinema Tools and FCP 3 workflow
(with some minor errors: batch processing requires clips that start
on A frames, not clips with A frames on 0s and 5s; and batch
processing needs F1-F2 or Field 1 Only selected depending on whether
you're using 24p or 24p Advanced footage, just like manual processing
does).

General 24p Information

24p.com has lots of useful info,
especially the links on its Resources page.

Other 24p SDTV cameras

The Canon XL2, US$5,000, has
a 16x9 native CCD, 24p and 24p Advanced, and uses all Canon XL-series
accessories. Like the XL1 and XL1s (and the DVX100), it records
standard DV.

Kinetta will be delivering a
24p HD cinema camera; it runs any speed from time-lapse to 60fps, and
even offers hand-cranking!

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